Serena Williams has outlasted an injured opponent, older sister Venus Williams, to retain her title at the Wimbledon tennis championships in London, the sixth time they've met in the finals of a Grand Slam event.

Serena lost the first set Saturday, rallied to take the next one, then took command in the deciding set as Venus grimaced and played through the pain of a strained abdominal muscle 6-4, 4-6, 6-2. Early in the third set, Venus clutched her stomach and limped off the court, raising doubts as to whether she would be able to finish the match.

Venus, a two-time champion at Wimbledon, returned several minutes later to a big ovation from the Center Court crowd, but the velocity of her serves gradually fell off, and she could not stretch or move quickly enough to counter her sister's blistering shots. Venus has won four major titles, but none since beating Serena in the first all-Williams Grand Slam final at the 2001 U.S. Open. The family has won four consecutive titles at Wimbledon, with Serena defending her title.